dmaengine: dmatest: Return boolean result directly in filter()

There is no need to have a conditional for boolean expression when
function returns bool. Drop unnecessary code and return boolean
result directly.

While at it, drop unneeded casting from void *.

Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20200922115847.30100-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: andy-shev

drivers/dma/dmatest.c

@@ -1058,13 +1058,7 @@ static int dmatest_add_channel(struct dmatest_info *info,
 
 static bool filter(struct dma_chan *chan, void *param)
 {
-	struct dmatest_params *params = param;
-
-	if (!dmatest_match_channel(params, chan) ||
-	    !dmatest_match_device(params, chan->device))
-		return false;
-	else
-		return true;
+	return dmatest_match_channel(param, chan) && dmatest_match_device(param, chan->device);
 }
 
 static void request_channels(struct dmatest_info *info,